Although it seems like there is a new crossover vehicle announced every week, we've never seen one like this. The Ford 2007 Airstream Concept ($TBA) is instantly recognizable thanks to reflective paint, and a part airplane, part Airstream trailer design. The real beauty is under the hood, however. The vehicle is powered by a plug-in hydrogen hybrid fuel cell — named HySeries Drive — that operates under electric power and delivers the fuel economy equivalent of 41 miles per gallon.